Biomedical Engineering Reference
In-Depth Information
Table 12.1
Medical device types [10]
Function
Form
Therapeutic
Durable
Monitoring
Implantable
Diagnostic
Disposable
12.2.3 Medical Device Classification
Section 510(k) of the Food, Drug, and Cosmetic Act requires device manufacturers to
notify the FDA of their intent to market a medical device at least 90 days in advance. This
is known as premarket notification
also called PMN or 510(k). Once a determination
has been made that a product is a medical device, the next issue that must be addressed is
its classification. In other words 'What kind of submission do I need to commercialize this
device? Is it exempt from 510(k) notification requirements, subject to those requirements,
or must we file a premarket approval application (PMA)?' In order to answer these
questions, we first need to know the class of the device.
Regulatory control increases from Class I to Class III. Class I devices are the simplest
and are only subject to general controls since they pose the fewest risks. They must,
however, follow the regulations and have accurate labels and labeling. Furthermore, since
the manufacturer must register and list its devices with the FDA, it cannot, therefore, be a
banned device or be subject to a recall or similar action. Most Class I devices are exempt
from PMN requirements (510(k)
2
), and some are also exempt from compliance with
the quality system regulations (QSR). Examples of Class I devices include toothbrushes,
oxygen masks, and irrigating syringes. The FDA estimates that approximately half of the
medical devices it regulates are Class I devices.
If Class I controls are not, by themselves, sufficient to provide reasonable assurance of
safety and effectiveness, the device is placed in the Class II category, in which special
controls are imposed due to the moderate risk involved. In order to market a Class II
device in the United States, the manufacturer must obtain clearance of a 510(k) PMN
prior to commercialization. The purpose of this is to demonstrate that the new device is
substantially equivalent to either another device that has already gone through the 510(k)
process or one that was on the market before the Medical Device Amendments were
signed on 28 May 1976. Class II devices are subject to the special controls as outlined in
the Office of Device Evaluation (ODE) guidance documents, FDA-accepted international
standards, and the QSR. These controls include a review of performance standards, post-
market surveillance, patient registries, and submission of guidelines (including clinical
data in PMN). Devices that fall into this category include ultrasound imaging systems,
Holter cardiac monitors, pregnancy test kits, and central line catheters. The FDA esti-
mates that slightly less than half of the medical devices it regulates are Class II devices,
of which approximately 3200 are cleared each year for use on the US market [11].
If general controls and special controls (Classes I and II) are still insufficient to ensure
the safety and efficacy of the device, an application for Class III (premarket) approval
−
2
These notifications, usually called 510(k)s because they are regulated by section 510(k) of the Medical Device
Amendments, are reviewed by the FDA.
